Variables

• Define independent variable

  The variable that is manipulated by the researcher
• Define dependent variable

  The variable that is measured by the researcher
• What are extraneous variables?

  The variable (other than the IV) that potentially affects the DV in a non-systematic way
• What are confounding variables?

  The variable (other than the IV) that potentially affects the DV in a systematic way
• What are participant variables?

  Type of extraneous variables related to the individual differences between participants which may affect the DV e.g. IQ
• What are situational variables?

  Type of extraneous variables relate to the differences in the environment of the experimental situation which may affect the DV e.g. temperature, time of day, weather.
• What are demand characteristics?

  Cues from the experiment allowing the participant to work out the purpose of the experiment
• What are investigator effects?

  Effect of the investigator on the DV - this may be conscious or unconscious e.g. smiling at participants giving correct answers or asking leading questions.
• What is randomisation?

  Use of chance to reduce the researcher's influence on the investigation e.g. order of word lists are random - controls for investigator effects
• What is standardisation?

  Using exactly the same formalised procedures and instructions for all participants in a research study - controls for situational variables